char* convertToTitle(int columnNumber)
{
           char *ans;
       while(columnNumber!=0)
       {
        int remainder = columnNumber % 26;
        if(remainder==0)
        {
            remainder = 26;
            columnNumber -= 26;
        }
        ans += remainder + 'A'-1;
        columnNumber /= 26;
       }
       printf("%s",ans);
    
}


